The rhodium speciation in nitric acid has been identified, primarily by
the use of
103Rh
Nuclear Magnetic Resonance Spectroscopy. The results
have indicated that the rhodium species in stored high level waste (HLW)
will range from the hexaaquo ion, {Rh(H20)6}3+-to complexes of the
general formula {Rh(H20)6-n(NO2)nl(3-n)+, depending on the nitrite
ion concentration.
The solvent extraction of these complexes by dinonylnaphthalene sulphonic
acid and various organo-phosphine sulphides has been investigated,
and an integrated scheme for recovering rhodium from HLW is proposed.

Description:

Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.